Idle AFR's for dynoing

[Chalky]

I dyno'd last year and made a bunch of pulls. I finally got around to looking at the results. The car was a baseline 02 Z06 with headers and different AFR's from 11's to high 13's. I looked at the results from 3000 to 6500 rpm.

I looked at the results with the best HP at various rpms. I use the best HP and AFR #.s For the most part, you can also richen up AFR by 2-3 tenths and have what I consider negligible effects on HP.

Keep in mind, this is based on my experiences only and my setup.

HTH

[SOMhaveit]

So this was with the LS6 heads/cam? Had you modified timing or other aspects of the original tune?

[Chalky]

Everything was stock accept for headers. I may have had a blackwing filter on, can't remember.

Going back to dyno tomorrow or Tuesday hopefully and try a couple of different configuration of AFR just for comparisons.

[SOMhaveit]

I'm not surprised at all at the AFR #'s your car performed best at.

I haven't been back to the dyno since working on my tune, but it seems like my car runs very well at 13.1 WOT.

[SSpdDmon]

I wonder how far off the numbers would be at 12.8:1 across the board? I'd rather have a little margin of safety for the long term I guess knowing that the car will perform differently from day to day.

[Chalky]

The car was also dyno'd on 93 octane 10% ethanol.

I just found it interesting that the car liked a progression from toward an accepted AFR of say 12.9:1. I have seen some PE tables go straight 12.9:1 across the board.

FWIW, when I looked at different AFR settings by RPM per PE table, a shift is a couple of a tenth or two did not show an appreciable difference in power loss. Using my examples, the results I attached were the sweetspot for my car.

I want to try my settings as well as other settings with extra fuel @ max tq readings.